Vat dye printing



Patented July 25, 1933 UNITED STATES PATENT OFFICE LUDWIG mcrrrrmsrnm, or VIENNA, Aus'rRIA, AND JAKOB KLEIN, DECEASED, LATE OF KOENIGINHOF, GZEGHOSLOVAKIA, BY

OF BADEN, NEAR VIENNA, AUSTRIA HEDWIG MARTHA. KLEIN, EXECUTRIX,

VAT DYE PRINTING No Drawing.

This invention relates to printing cotton fabrics and the like with vat colors, and more particularly to the aging or fixing of such vat colors on the goods. The invention is applicable-to printing vat colors of the indigoid type or of the mixed indigoid and anthraquinone type.

The printing of vat colors under the usual commercial practice is vaccomplished by printing them with hydrosulphite preparations and afterward aging them by a steaming processor the like. Early attempts to employ glucose as a reducing agent for vat colors of the indigoid or mixed indigoid and anthraquinone type were .not entirely'successful, due partly to the fact that the reduction by. glucose in the steaming was too slow and the fixation not sufliciently strong.

Important objects of thepresent invention are to improve the quality of the work, to obtain better economy and reliability of operation, and to avoid certain of the disadvantages or difliculties which are encounteredin printing with the usual hydrosulphite paste, or in the earlier attempts to fix the vat colors by the glucose process.

It has been found that the action 'of glucose in the steaming process can be satisfactorily accelerated by means of catalysts, to such an extent as to equal or even surpass the action of rongalites. The catalysts which it has been found can be used for this purpose are the anthraquinones, such as anthroquinone itself and its derivatives, which can be transformed into their corresponding oxyanthranolic compounds, as well as these latter compounds themselves, also other compounds containing carbonyl groups in paraposition which can be reduced, their potency eing governed by the ease with which they are reduced. Substituted anthraquinone derivatives which may be mentioned as examples are methyl-, ethyl-, chloror bromanthra uinone and the/like, as well as those derivatives of anthraquinone'which contain the halogen on the side chain as, for example, brom-methyl-anthraquinone, and as further examples those which contain groups forming salts. Additional catalysts which can be regarded as equivalents under the Application filed October 1, 1931. Serial No. 566,320.

paste, the essential difference being that the fixing or aging of the vat color on the goods is accomplished by the action of glucose or similar carbohydrates, or stannous oxide, in the presence of alkali of substantially the strength of alkali metal carbonate and a catalyst. easily handled as the hydrosulphite printing pastes, while at the same timethey are cheap and produce a high yield. In the case of hand printing they offer the special advantage over the hydrosulphite paste process that the reducing agent does not decompose in the printing paste on slowdrying so that the printed cloth can even remain for days without being aged, and without danger of losing an depth of shade or yield in color.

The followlng will serve as examples of printing pastes, which can be employed in accordance with the invention.

EXAMPLE 1 Printing paste 40 grams brome-indigo 40 grams glycerine grams silver salt (sodiumbeta-anthra quinonemonosulphonate) 20 grams water 840 grams thickening BL Thickening BL These printing pastes are just as 6 are accomplished, forexample, by passing 1 the goods through the usual steaming chamlid her at about 215 F. for tour or five minutes, after which the code are reoxidized in any of the stander developers such as weak sulphuric acid and sodium bichromate, this step being followed by washing in water, then soaping at boiling temperature, and finally washing and drying the goods.

Examines 2 Printing paste 40 grams d estufi powder 40 grams g ycerine grams water 60 grams silver salt (beta-anthraquinonesodium-sulphonate) 780 grams thickening 200 grams dyestud paste 60 grams silver salt 740 grams thickening Thickening paste 405 grams starch 1/5 gramsartificial gum (crystal) 1/3 grams glycerine 105 grams sodium carbonate 270 grams glucose 1/1 r ure in brackets is the number contained 1n Schultz corresponding to the number in Color Index.

The finishing of the goods may follow substantial]. the procedure outlined in connection with Example 1.

1n the above examples anthraquinone or any of its derivatives which are transformed by reducing agents into their corresponding oxy-anthranoi reduction products can be substituted for the silver salt, and stannoue neravea oxide can be employed in place of glucose. Uther carbohydrates similar to glucose may likewise be employed in place of the glucose or stannous oxide. While these stated substances are equivalents in general of the silver salt and glucose, the use of glucose in conjunction with silver salt is s ecifically preferred as giving the most satis actory results and ofiering the greatest commercial advantage.

Since the use of glucose in conjunction with a catalyzer of" the character described discharges all dyeings which are dischargeable with hydrosulphites, these printing pastes can be used on colored goods. The mrm rinting is thus to be understood in the claims as including discharging.

The term indigoid type is employed in the claims to indicate not only the strictly indigoid dyestufis, but to include as well those which are recognized as a mixture or combination of indigoid and anthraquinone character.

it is claimed:

1. The method of printing with vat dyestufis of the indigoid ty e, which comprises as an essential step the xing of the dyestuii by means of glucose in the presence of alkali metal carbonate and an anthraquinone or derivative thereof, transformable readily 3y reducing agents, into its oxyanthranoi corresponding oxyanthranolic derivative,

2. The method of printing with vat dye stufis of the indigoid type, which comprises applying to the goods a composition containing the indigoid dyestufii, glucose, an anthraquinone catalyst and an alkali metal carbonate, ageing the same in steam, and reoxidizing in a developer.

3., The method of printing with. vat dyestufis of the indigoid type, which comprises the fixin of the dyestuff by means of glucose in the presence of silver salt acting as a catalyst and alkali of substantially the strength of alkali metal carbonate.

LUDWG LTCHTENSTETN. HEDWIG MARTHA KLETE, Exec atria of the Estate of Jakob Klein,

Deceased.

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